Electric switch



May 'Zip 1929. H. A. DQUGLAS ELECTRIC SWI TCH Filed Nov. 17, 1972.7'

Patented May 7, 1929.

UNITED STATES HARRY A. DOUGLAS, OF BRONSON, MICHIGANL ELECTRIC SWITCH.

. Application filed November 17, 1927. Serial No. 233,873.

My invention relates'to electric switches and resides in the provision of improved means for moving one of two complemental contacts into and out of engagement with the other.

In carrying out my invention, the movablecontact is spring pressed and controlling means are employed for limiting the eifective spring pressure upon the movable contact to one direction to engage the movable contact with the other and to thc reverse direction to separate the movable contact from the other. The movable contact is desirably provided upon a carrier. This carrier is provided with a fulcrum and the controlling means serves to limit the effective spring pressure to one side or the other of the fulcrum point according to the direction in which the carrier and the contact thereon are to be turned.

The means for applying the spring pressure to the carrier is desirably in the form ofv a spring which is separately formed from the carrier, this spring being preferably stationarily located while the ulcrum is shiftable from eithery side to the other of the spring. This fulcrum is, in the preferred embodiment of the invention, provided upon a switch handle that is reciprocable to place the fulcrum point on one side or the other of the spring, though the invention is not to be limited to rectilineal movement of the handle. Two stationary contacts are desirably provided and two movable contacts are alsoprovided which are respectively complemental to the stationary contacts, the two movable contacts being preferably separately formed from the contact carrier and in electrical connection with each other whereby they. are included in the same circuit with the sationary contacts when the switch is clos T e invention will be more fully explained by reference to the accompanying drawing in which Fig. 1 is a longitudinal sectional view of, the preferred embodiment of the invention, the switch handle and the fulcrum thereon being shown in elevation, the switch,

as illustrated in this figure, being in circuit closing position;.Fig. 2 is a sectional view on line 2 2 of Fig. 1; Fig. 3 is a sectional view on line 3 3 ofv Fig. 1; Fig. 4 is a sectional view on line 4 4 of Fig. 1; Fig. 5 is a view of some of the parts illustrated in Fig. 1 showing the switch in a circuit openingJposition, some of the parts which are shown in section in Fig. 1 being illustrated in elevation in this Fig. 5; Fig. 6 is a secn tional view on line 6 6 of Fig. l; and Fig. 7 is a perspective view illustrating the contact carrier and the contacts thereon.

The switch illustrated is provided with an enclosing casing having a cylindrical cupshaped portion 1 which has a hollow stem continuation 2, this stem being threaded to receive clamping nuts 3 and 4 between which the support 5 for the switch may be clamped.

vAn insulating disc 6 closes or covers the cup,

this disc being held against the edge of the cup by means of clips 7, formed upon the cup, these clips being received within notches formed in the edge of the disc and being turned over upon the-disc at their outer ends. Said disc carries the stationary metallic contacts 8 and 9, these contacts be= ing preferably in the form of posts having flanges 10 and 11 which engage an'inner face of the disc and lianges or heads l12 and 13 at the outer side of the disc and which are riveted into engagement with the metallic terminal clips 14 and 15 which are tightly held against the outer face of the d1sc. Binding screws 1 6 and 17 serve lto clamp the circuit wires 18 and 19 into me:l chanical and electrical engagement with the cli'ps 14 and 15.

he movable contacts that are complemental to the stationary contacts are'provided upon and are integrally formed with the V-shaped metallic plate 20, the end p ortions of this plate being respectively en s gageable with said posts. The plate 20l is formed with clips 21 that are received with- 1n notches formed within the insulating block 22 which is clinched by these clips against this plate 20. The block 22 constitutes a part of the carrier for the movable contacts, the balance of the carrier being inclusive of a metallic plate 23 which is provided with clips 24 that are received within notches formed in the block4 22 and are clinched into enga ement therewith, these I being creceived within a spring barrel 27 p assembled with the cup 1. This spring barrel is disposed upon a radius of the cupshaped portion 1 as is also the spring 28 contained in the spring barrel. This spring maintains the outer end of the plunger 26 in the socket 25. The carrier plate 23 is positioned, at 011e end, by a iin) or rib 29 whichis mounted upon the insulating disc 6 and enters the recesses 30 and 31 that are respectively 'formed in one end of the plate 23 and the adjacent'side of the insulating block 22. These recesses and the aforesaid fin also extend radially with reference to the cup 1 and take part in guiding the movement of the carrier 22,23 upon a radius of the cup as also does the radially spring pressed plunger 26.. The plate 23 is provided with ears 32 which embrace the spring barrel 27 whereby the radial movement of the plate is guided.

The contact carrier comprising the block 22 and plate 23 thus floats, the circuit opening Ior closing position of the carrier being positively delined by the fulcrum 33 which is preferably in the form of a flange upon a switch handle 34 that is desirably slidable within the bore of. the cup stem 2, said handle having a gripping knob 35. When this handle is in its outermost position, the fulcrum 33 engages the adjacent end of the plate 23 so that the spring 28 is then effective to move the contact plate 20 against the contact terminals 8 and 9as illustrated in Figs. l and 2. As illustrated in these figures, the effective pressure of the spring is limited to a location between the fulcrum 33 and the Contact plate 20. When the handle 34 is moved to its innermost position, the ulcrum 33 is placed `in its alternative position, Fig. 5, the fulcrum then being between the spring and the contact plate 20,

ywhereby the cont-'act plate 20 is withdrawn from the contacts 8 and 9, the ef fective pressure of the spring being now upon the other side of the fulcrum point. It will be -observed .that the direction of the spring .pressure in either position of the fulcrum is substantially parallel with the direction Iof movement of the contact plate 20 and its carrier. The portion of the plate `23 between the alternative positions of the ulcr'um 33 is desirably bent to form a hump 23 in the path of movement ofv the fulcrum whereby the fulcrum is held in either of its alternative positions, the Ioutward movement of the handle 34 and the fulcrum 33 being also limited by engagement of said fulcrum with the inner end of the cup stem 2.

Changes may be made without departing from the invention.

Having thus described ,my invention, I claim:

1. In an electric switch, the combination with a contact; of a carrier having a contact thereon that is complemental to the aforesaid contact; a fulcrum upon which said carrier may be turned, said carrier being spring pressed to effect turning movement thereof; and means whereby said fulcrum may be shifted to bring the effective spring pressure upon one side of the other of the fulcrum point to open or close the switch.

2. In an electric switch, the combination with a Contact; of a carrier having a Contact thereon that is complemental to the aforesaid contact; a fulcrum upon which said carrier may be turned, said carrier being spring pressed to effect turning movement thereof; and a reciprocable handle coupled with the fulcrum and serving to shift the fulchrum point to one side or the other of the place of effective spring pressure to open or close the switch.

3. The structure of claim l. wherein the carrier is provided with a hump whichis interposed between the alternative positions of the fulcrum to take part in holding the fulcrum in such positions.

4. The structure of claim l wherein a spring separately formed from the carrier presses upon. the carrier in the direction of movement of the movable contact.

5. The structure of claim 2 wherein the carrier is provided with a hump which is interposed between the alternativepositions of the ulcrum to take part in holding the ulcrum in such positions.

6. Ihe structure of claim 2 wherein a spring separately formed from the carrier presses upon the carrier in the direction of movement of the movable contact.

witness whereof, I hereunto subscribe my naine.` Y

HARRY A. DOUGLAS.` 

